Certain cholesteric liquid crystal compositions are known which change to the nematic state upon application of an electric field. Wysocki et al. in Phys. Rev. Letters 20 No. 19, page 1024 (1968) reported that cholesteryl chloride, alone or in admixture with other cholesteryl derivatives including cholesteryl nanoate and cholesteryl oleyl carbonate, underwent a change from the cholesteric to the nematic state when an electric field was applied. Thus, an electro-optic cell including such materials changed from a light scattering, opaque appearance to a clear, colorless appearance when a direct current field of about 10.sup.5 V/cm was applied. Such cells thus require a fairly high voltage and they have the further disadvantage that they have limited use temperature ranges. Thus, a similar electro-optic device which would be operative over a wider use temperature range, including room temperature, and would require lower voltage to operate than those known heretofore, would be highly desirable.